A spectacle lens is usually designed through a simulation step and an evaluation step thereof. In the simulation step, an eyeball model and a lens shape are constructed by a computer according to computer simulations, a beam of light that has passed through a lens is then evaluated, and the lens shape is optimized so as to bring its evaluation result close to a desired value. Based on a design value designed in the simulation step, a lens to be evaluated (hereinafter, referred to as a “to-be-evaluated lens”) is actually produced, and optical measurement, shape confirmation, and monitor spectacles-wearing evaluation are performed in the evaluation step. Thereafter, improvements in design are advanced in such a way that the result obtained in the evaluation step is again fed back to the desired value of the simulation step. The “optical measurement” denotes that the produced to-be-evaluated lens is evaluated about whether the lens is the same in optical characteristics as a simulated one, and the “shape confirmation” denotes that the produced to-be-evaluated lens is likewise evaluated about whether the lens has been formed in accordance with a lens surface shape corresponding to data designed by the computer by actually performing tracing by use of, for example, a three-dimensional shape tracer, and the “monitor spectacles-wearing evaluation” denotes that a subject's impression received by actually wearing spectacles having the produced to-be-evaluated lenses is evaluated. Patent documents 1 and 2 can be mentioned as examples of prior arts disclosed with respect to a method for designing spectacle lenses and its evaluation.
Herein, when a spectacle lens is designed, this lens can be designed with the expectation that a sensation felt when spectacles are worn will be improved to some extent by a computer simulation. However, after all, a judgment about whether such a spectacles-wearing sensation is good or bad cannot be made until the spectacles are actually worn, and therefore the importance of the monitor spectacles-wearing evaluation occupies a large percentage in the evaluation step. Especially in a progressive power lens, there are many cases in which a larger-than-expected difference is felt between a design imaginarily set by a computer simulation and a sensation given when spectacles using the progressive power lenses are actually worn, and therefore the monitor spectacles-wearing evaluation is important.    Patent Document 1: Japanese Published Unexamined Patent Application No. 2006-72192    Patent Document 2: Japanese Translation of International Application No. 2006-506667